B&W unveils modular nuclear power design

Babcock & Wilcox (B&W) has announced plans to develop and deploy a scalable, modular nuclear power reactor. US utilities have already expressed an interest in the 125 MWe design.

A nuclear power plant utilizing mPower reactors. Work towards certifying it for US deployment could begin next month with a full application reaching regulators in 2011. (Image: B&W)

The company, a subsidiary of McDermott International, describes the mPower reactor design as "a passively safe Advanced Light Water Reactor (ALWR) with a below-ground containment structure," and is air-cooled. According to B&W, "this optimized ALWR represents true Generation III++ nuclear technology that B&W believes can be certified, manufactured and operated within today's existing US regulatory, industrial supply chain and utility operational infrastructure."

The mPower is an integral PWR designed to be factory-made and railed to site. The reactor pressure vessel containing core and steam generator is thus only few metres diameter. It will have a "conventional core and standard fuel" enriched to 5%, presumably with burnable poisons, to give a five-year operating cycle between refuelling. This is intended to provide a low-cost approach to plant operations. B&W added that nuclear security and near-term management of used fuel would be improved through the underground containment design that will store fuel for the planned 60-year life of the plant.

B&W said that the "scalable nature of nuclear power plants built around the B&W mPower reactor would provide customers with practical power increments of 125 MWe to meet local energy needs within power grid and plant site constraints." Several units would be combined into a power station of any size, but most likely 500-750 MWe and using 250 MWe turbine generators (as illustrated), constructed in three years.

The company added that it expects the use of "proven ALWR design features, together with a passive safety philosophy, to minimize plant licensing challenges, enhance safety performance and contribute to reliable plant operation."

Brandon Bethards, CEO of B&W, said that the company had notified the US Nuclear Regulatory Commission (NRC) in April that it intends to seek design certification for the new reactor and that it plans to begin pre-licensing activities in July. According to Bethards, B&W expects to submit its application for design certification of the reactor in 2011. He said that potentially an application for a combined construction and operating licence (COL) referencing the reactor design could be submitted to the NRC around 2012. This could see construction of the first plant utilizing the design starting in 2015, with operation beginning in 2018.

The nuclear steam supply system (NSSS) for the mPower reactor will be manufactured in existing B&W facilities in North America and then shipped by rail to construction sites. The company added that it has already received a letter of intent from utility Tennessee Valley Authority (TVA) to begin the process of evaluating a potential lead site for the mPower reactor (reported elsewhere to be Clinch River). In addition, a memorandum of understanding has been signed by B&W, TVA and a consortium of regional municipal and cooperative utilities to explore the construction of a fleet of mPower reactors to meet the consortium's need to diversify its power generation assets.

B&W said it has also assembled a global team of potential future customers to support the development of the reactor to make sure it meets customer and regulatory requirements in North America, Europe and elsewhere.